Granted Patent
Utility
US 6,218,342 · App. 08/862,201
Oil-based drilling fluid
Inventor:
Avind D. Patel
Patented Case
View Patent ↗
Granted: Apr 17, 2001
Filed: May 23, 1997
Inventor
Avind D. Patel
Assignee (at issue)
M. I. Co., Ltd.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.